In 1995, Professor Chou who is currently at Princeton University and others developed a novel technology called nanoimprint lithography (Patent Document 1). The nanoimprint lithography is a technology in which a mold having any pattern is caused to contact with a base material on which a resin film is formed; and pressure is applied to the resin film while applying an external stimulation such as heat and light to form a desired pattern on the cured resin film. The nanoimprint lithography makes simple and low-cost nanoscale processes available, and thus is advantageous compared to conventional photolithography and the like used for manufacturing semiconductor devices.
The nanoimprint lithography is expected to be applied to manufacture of semiconductor devices, optical devices, displays, storage media, biochips, and the like, instead of photolithography, and thus various reports about curable compositions for photonanoimprint lithography used for nanoimprint lithography have been published (Patent Documents 2 and 3). In addition, a photoimprint material containing a compound having a silicone skeleton and a photopolymerization initiator is described in Patent Document 4; and a curable resin composition for transfer materials used to form a fine pattern by an imprint method, which contains a compound having a silsesquioxane skeleton and a polymerization initiator is described in Patent Document 5.
When an expensive mold is used in nanoimprint lithography, the life of the mold needs to be longer; however, if a force for peeling the mold from a cured resin film, that is, a peel force at the time of mold release (hereinafter referred to as a “mold release force”) is large, the resin tends to adhere to the mold and the mold tends to become unusable. Accordingly, a low mold release force (a characteristic to easily peel a cured resin film from a mold) is required for a material used for nanoimprint lithography (hereinafter referred to as “imprint material”). Also, an external force is sometime applied to a resin film at the time of manufacturing devices, and a resin film deformed by such a force cannot be used for devices. Thus low plastic deformation, that is, a low plastic deformation characteristic is required. For manufacture of devices, heating processes such as baking and soldering may be taken. The temperature in the heating processes may be around 265° C. If the heat-resistance of a resin film to such temperature is low, a degradation product will be sublimed from the resin film, causing contamination of insides of devices, as well as apparatuses and equipment for making the devices. In addition, if the film has low resistance to stress generated at cooling from high temperature, the film will be cracked and defected. As the thickness of a film becomes larger, the film will be cracked more often. Some devices may be used under a heating environment, and will have the same problems. Therefore, in the products such as solid-state image sensing devices, solar cells, LED devices, and displays, the structure manufactured as an optical component is required to be highly heat resistant and crack resistant. To date, a variety of materials have been disclosed as imprint materials; however, any of them do not have all of: a low mold release force, a low plastic deformation characteristic, heat resistance that does not allow a degradation product to be sublimed at a temperature over 200° C., such as 265° C., and crack resistance.